Analysis of copy number variation by CMA in fetus with increased nuchal translucency
10.3760/cma.j.issn.0529-567x.2018.10.004
- VernacularTitle:颈部透明层增厚胎儿中CMA技术检测拷贝数变异的分析
- Author:
Liu DU
1
;
Hongning XIE
;
Ju ZHENG
;
Miao HE
Author Information
1. 中山大学附属第一医院超声医学科
- Keywords:
Nuchal translucency measurement;
Ultrasonography,prenatal;
Microarray analysis;
DNA copy number variations
- From:
Chinese Journal of Obstetrics and Gynecology
2018;53(10):671-676
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigated the clinical value of chromosomal microarray analysis (CMA)in fetuses with increased nuchal translucency(NT). Methods Totally 101 cases out of 19261 singleton fetuses who underwent the first trimester(11-13+6 weeks)ultrasound examination from January 2015 to June 2017 at First Affiliated Hospital of Sun Yat-sen University were diagnosed with NT ≥2.5 mm and underwent invasive prenatal test for fetal karyotype and CMA. According to the combination of other ultrasound abnormalities,the cases were divided into isolated group(67.3％, 68 / 101)and complicated group(32.7％, 33/101). In addition, the cases were divided into 5 groups according to the thickness of NT,2.5-2.9 mm(borderline thickening;16.8％, 17/101), 3.0-3.4 mm(33.7％, 34/101), 3.5-4.4 mm(16.8％, 17/101),4.5-5.4 mm(15.8％, 16/101),and ≥5.5 mm(16.8％, 17/101). Chi square test was used to detect the different rates of other combined ultrasound abnormalities and abnormal chromosome between 5 groups. Results The median thickness of NT was 3.4 mm(2.5-8.5 mm). And 32 cases(31.7％, 32/101)had abnormal karyotype. There was a significant difference in the frequency of abnormal karyotype between the isolated and the complicated group(20.6％ vs 54.5％, P<0.01). Among 69 cases(68.3％,69/101) of normal karyotype, 3 cases(4.3％, 3/69)were detected with pathogenic copy number variation(CNV) by CMA. Thirty-five cases with chromosomal abnormalities(include abnormal karyotype and pathogenic CNV), there was a significant difference in the frequency of chromosomal abnormalities between the isolated and the complicated group(23.5％ vs 57.6％, P=0.001). The median age of pregnant women in 5 groups was 35 years(24-39 years),33 years(23-46 years),31 years(21-46 years),33 years (21-41 years) and 35 years (21-43 years). The rates of chromosomal abnormalities increased with the increase of NT thickness. There was significant difference in the incidence of associated chromosomal abnormalities among 5 groups(P<0.05). Comparative analysis within the 5 groups, the incidence of associated chromosomal abnormalities between NT 2.5-2.9 mm and ≥5.5 mm was significantly different (P=0.005), while the differences between the other groups were not significant(P>0.05). Conclusions There is a high risk of fetal chromosomal abnormalities in borderline NT thickening (2.5-2.9 mm)at advanced maternal age, but the pathogenic CNV is not detected. Chromosomal microdeletion or microduplication could be further detected in the NT thickening(≥3.0 mm)fetuses with normal karyotype by chromosome microarray analysis, while the positive rate is relatively low, and the variants of unknown significance might be detected.
